A major part of today's advanced industrial products use some sort of electro magnetic energy converters, for example electrical motors, loudspeakers, microphones, sensors and actuators for opening/closing slides (e.g. DVD players), feeding bank notes (cash dispensers) etc.
Almost all of these are standard motors/components of very conventional type where the production methods and possibilities of integrating components within a product haven't been developed much during the last century.
Conventional motor manufacturing involves the punching and stacking of transformer sheets. Since the cost of punches is high, the production volumes must be considerable to have acceptable production costs. Further, since only a two-dimensional magnetic flux can exist in a machine using stacked transformer sheets, the complexity of the electric circuits will have to be high, resulting e.g. in a lot of interconnected coils, often wound directly on the motor teeth. In order to produce such a machine, a lot of manual work has to be done, making them expensive.
The highest possible frequency that can be used in a transformer sheet machine is given by the thickness of the individual transformer sheets. Using less than 0.2 mm thickness will result in a very expensive machine, thus disqualifying reasonably priced machines for designs with high speeds or/and high pole number.
Another example having essentially the same drawbacks as the electrical motors is conventional inductors, chokes etc., the important difference being, that since the permeability of most used inductor core materials is rather high, an air-gap has to be introduced in order not to saturate the core material. If the coils are wound over the air-gaps there will often be considerable fringing losses, resulting in a hot-spot which can be hard to cool.
Also conventional induction heating coils display a related problem. These coils are, almost without exception, built with liquid cooled copper tubes. The copper tubes will have very limited effective current-conducting area due to the skin effect at high frequencies. This naturally results in low efficiency, but even worse, the total resulting flux will not be able to penetrate the copper tubes, thus resulting in induction heating of the tubes. Further, the manufacturing of the copper tubes is time consuming manual labour.
A first step towards an elimination or alleviation of all of the above problems has emerged during the last decade, with the birth of a new material technology. This new material technology provides almost unlimited possibilities to specially adapt, optimize and integrate these types of actuators in consumer products as well as industrial products. The material technology in question is composites of soft magnetic metallic materials with varying amount of binder and filler, named Soft Magnetic Composites, SMC. The forming of these components made of SMC is of great interest, since the demands on high density and design freedom are in conflict with the known manufacturing methods. A successful forming process will result in an energy converter, which in many ways is superior to conventional ones in terms of lower losses, smaller size, a more compact integration in the driven device/product.
The present invention aims at providing a new and improved method and apparatus for production of SMC-components, as well as SMC-components manufactured with such a method.